This invention relates to foot propelled vehicles, such as bicycles, tricycles, or pedaled boats, and is more particularly directed to a pedaled propulsion system in which reciprocating levers are worked by the rider or operator, rather than a rotary crank, to power the wheels or other propulsion mechanism. The invention is certainly not limited to wheeled vehicles but can also be applied to boats or float-supported vehicles, or runner-supported vehicles for snow or ice travel.
A number of foot lever or pedal lever based systems for propelling bicycles have been proposed and some of these are described in the U.S. patent literature. Of some general interest here are Silvano et al. U.S. Pat. Nos. 4,872,695; Hege 3,984,129; and White 1,148,419. Silvano et al. combines a conventional crank and front sprocket with a pedal and slide bar system to change the mechanical advantage of the cranks. Hege describes a reciprocating foot lever system for propelling a bicycle. A strap is coupled to the rear wheel hub and to a respective foot lever arm, and turns the rear wheel, the two sides of the wheel hub operating in turn. The levers are connected to a gear mechanism inside the wheel hub. This is a rather complex arrangement, and requires drastically modifying the rear wheel from the standard chain drive configuration. White employs a rack and pinion system where an arcuate toothed sector engages a toothed sprocket on a rear wheel hub. Spring returns are included to return the foot levers to their upwards positions.
These systems tend to be rather complex and fail to achieve optimal mechanical advantage for the rider.